The present invention relates to a dial type operating device.
In the related art, for example, there is an operating device shown in FIG. 4 as an operating device which is provided for an air conditioning operation of vehicles. In the operating device, from the left side in FIG. 4, a dial 1, an indication piece 2, a display panel 3, a panel support 4, a body 5, a push button 6, a light guiding piece 7, an intermediate gear 8, a switch 9, a LED 10, resistors 11 to 13, an insulator 14, a lamp 15, a final stage gear 16, a housing 17, and a pulley unit 18 are present in this order.
The dial 1 is formed in a hollow short cylindrical shape. The indication piece 2 is mounted on one place of an inner circumferential portion of the dial. The front end of the indication piece 2 is exposed forward from a recessed portion 19 of a leading edge of the dial 1. In addition, gear teeth 20 are formed in an inner circumferential portion of a rear portion of the dial 1.
The display panel 3 is formed in a circular sheet having a hole 21 in the center portion, in this case, a plurality of displays 22 which display a level of a set temperature in the interior of a cabin of a vehicle are annularly disposed in the front surface of the display panel 3, and the display panel 3 is attached to a front surface of the panel support 4. The panel support 4 is concentric with the hole 21 of the display panel 3 and includes a ring portion 23 which has substantially the same diameter as that of the hole 21.
The body 5 includes a large cylindrical portion 5b and a small cylindrical portion 5c which are concentrically disposed with respect to each other in the front of a polygonal box-shaped portion 5a. The panel support 4 is fixed to a leading edge of the small cylindrical portion 5c. The dial 1 is rotatably fitted to an outer circumference of the large cylindrical portion 5b. As result, the display panel 3 is exposed forward from an opening portion 1a of the front surface of the dial 1.
In this case, a display 24 of characters (NC) of an air conditioner and a light-transmitting window 25 are provided in the front surface of the push button 6. The light guiding piece 7 is inserted to a portion which extends to the light-transmitting window 25. The push button 6 is inserted from the small cylindrical portion 5c of the body 5 to the ring portion 23 of the panel support 4 and exposed forward from the hole 21 of the display panel 3.
The intermediate gear 8 includes gear teeth 8a in the front portion and gear teeth 8b in the rear portion. The gear teeth 8a of the front portion are inserted into a hole (not shown) which is formed in the lower portion of the polygonal box-shaped portion 5a of the body 5 and are meshed with the gear teeth 20 of the dial 1.
The switch 9, the LED 10, and the resistors 11 to 13 are mounted on the insulator 14 from a front side, and the lamp 15 is also mounted on the insulator 14 from a rear side. Moreover, a notch 26 is formed in the lower portion of the insulator 14, the gear teeth 8b of the rear portion of the intermediate gear 8 are inserted into the notch 26, and therefore, the insulator 14 is combined with the body 5. In addition, a connector 27 is integrally formed in one place of the outer circumferential portion of the insulator 14, a mating connector (not shown) is connected to the connector 27, and the switch 9, the LED 10, the resistors 11 to 13, and the lamp 15 are electrically connected.
The final stage gear 16 is formed in a short cylindrical shape having a bottom, gear teeth 28 are formed in the inner circumferential portion of the gear 16, and the gear teeth 28 are meshed with the gear teeth 8b of the rear portion of the intermediate gear 8. In addition, a noncircular volume shaft fitting hole 29 is formed in the center portion of the final stage gear 16.
The housing 17 accommodates the final stage gear 16 and is formed in a polygonal box shape which is combined with the polygonal box-shaped portion 5a of the body 5 while interposing the insulator 14, and a circular volume shaft inserting hole 30 is formed in the center portion of the housing.
The volume 18 is configured such that a noncircular hollow shaft section 18b is projected from a case 18a, and a variable resistor (not shown) having a resistance value which varies the resistance value in accordance with rotation of the shaft section 18b is accommodated in an inner space of the case 18a, and the shaft section 18b is passed through a volume shaft inserting hole 30 of the housing 17 and is inserted and fitted into the volume shaft fitting hole 29 of the final stage gear 16. In addition, a lead wire 31 adapted to transmit a resistance output to a control device (not shown) is led out from the case 18a of the volume 18 to the outside.
With the above configuration, when an operator grips and rotates the dial 1 by a hand, the rotation is transmitted from the gear teeth 20 to the gear teeth 8a of the intermediate gear 8 at its front portion and the rotation is further transmitted from the gear teeth 8b of the intermediate gear 8 at its rear portion to the gear teeth 28 of the final stage gear 16. Accordingly, since the final stage gear 16 is rotated, the shaft section 18b is rotated through a noncircular engagement structure of the volume shaft fitting hole 29 of the final stage gear 16 and the shaft section 18b of the volume 18. Thereby, the resistance value of the variable resistor (not shown) in the case 18a is changed and its resistance output is transmitted to the control device (not shown) through the lead wire 31. As a result, the control device determines a set temperature in the interior of the vehicle corresponding to a rotation angle of the dial 1 on the basis of the received resistance output and energizes a motor (not shown) adapted to operate a dumper for controlling a temperature of air supplied to the interior of the vehicle so as to adjust the temperature.
Meanwhile, the display 22 of the display panel 3 is adapted to display the temperature adjusted as described above, and the indication piece 2 indicates a position (corresponding to the rotation angle of the dial 1) of any of the displays 22 of the display panel 3, that is, the indication piece 2 indicates a set temperature position in association with the rotation of the dial 1. At that time, the lamp 15 illuminates the entirety of the displays 22 from the back side of the displays 22. Therefore, the displays 22 has light translucency.
When an operator carries out a pressing operation of the push button 6 by a fingertip, the switch 9 which is mounted on the insulator 14 is pressed and operated, and an output thereof is transmitted to the control device through a lead wire (not shown) from the connector 27 of the insulator 14 so that an air conditioner is operated. With this, the LED 10 emits light, and the light passes through the light guiding piece 7, emerges in the light-transmitting window 25 of the push button 6, and displays the operation of the air conditioner (for example, refer to JP-A-2005-96579).
In the configuration of the related art, operational rotation of the dial 1 is transmitted to the gear teeth 8a of the intermediate gear 8 at the front portion from the gear teeth 20 of the dial 1 and further transmitted to the gear teeth 28 of the final stage gear 16 from the gear teeth 8a of the intermediate gear 8 at the rear portion so as to cause the final stage gear 16 to be rotated, and thereby the shaft section 18b of the volume 18 is rotated. The related art has a structure including two stages of gear transmission adapted to finally transmit the operational rotation of the dial 1 to the shaft section 18b of the volume 18.
A reaction or swingback referred to as a backlash inevitably exists in the transmission of rotation by gears so that the more the number of stages of gear transmission is increased, the more the backrushes are generated. Therefore, in the configuration of the related art, operational precision is lowered due to the backrushes and an adjusting operation by the dial 1 is not highly precisely performed. In addition, in the configuration of the related art, there are problems that the number of components is large and the cost is increased because of the two stages of gear transmission, and the reduction in size is difficult.
The invention is made in view of the above described circumstances, and the purpose of the invention is to provide an operating device capable of enhancing precision in an adjusting operation by a dial, and achieving reduction of cost and reduction in size by virtue of reduction of the number of components.